DaimlerChrysler Jeep Grand Cherokee 2002, Service Manual

Page: 240 / 284

Symptom:
*CHECKING THE WATER IN FUEL LAMP OPERATION
POSSIBLE CAUSES
ASD RELAY OUTPUT CIRCUIT OPEN
ECM
SENSOR GROUND CIRCUIT OPEN
VERIFY WIF INDICATOR OPERATION
WATER IN FUEL SENOR SIGNAL CIRCUIT OPEN
WATER IN FUEL SENOR SIGNAL CIRCUIT SHORTED TO GROUND
WATER IN FUEL SENOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND
WATER IN FUEL SENSOR
TEST ACTION APPLICABILITY
1 Perform the Instrument Cluster Self-Test to verify proper WIF Indicator operation.
Did the WIF Indicator operate correctly during Self-Test? All
Yes
→
Go To 2
No
→
Test Complete.
2 Turn the ignition off.
Disconnect the WIF Sensor harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the ASD Relay Output circuit at
the WIF Sensor harness connector.
Does the test light illuminate brightly? All
Yes
→
Go To 3
No
→
Repair the ASD Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the Water In Fuel Sensor harness connector.
Turn the ignition on.
With the DRB, read the Water In Fuel Switch state.
Connect a jumper wire across the Water In Fuel Sensor harness connector cavities 1
and 2 for 10 seconds then disconnect the jumper.
NOTE: The DRB display should read CLOSED with the jumper connected
and OPEN when the jumper is not connected.
Does the DRB Display switch between OPEN and CLOSED as described? All
Yes
→
The WIF Sensor circuitry and the ECM are functioning properly.
If there is still a WIF indicator problem replace the Water In Fuel
Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Go To 4
232
DRIVEABILITY - DIESEL
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